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Topic: Need a bit of help making a Mark III adapter (Read 3352 times)

I have a fully loaded Retrode 2, including the Master System adapter, but I've been buying a few Japanese Mark III/Master System games which I wanted to be able to dump.

There's a couple of threads already about various third-party adapters being tested, none working from what I can tell. So I thought I'd "make" my own. Here's my thinking, and do stop me if any of this sounds wrong.

And at this point I'm kind of stumped as to how to use all this information. I think I'm missing an "export SMS to Mark III diagram" somewhere. Ideally, it'd support Mark III and Japanese SMS games[1], but I already see some difference in wiring for some lines that the Retrode uses (though I could have had my numbers crossed).

i made this awhile back, it allows me to play sega cards on the master system model 2, play sega cards on the game gear with a master gear converter as well as dump sega cards on my retrode using a master system plugin.

although ive never tried im guessing it will also do SG-1000 cards too.

@hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

> @hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

Well, because it didn't work

I should probably have added this information in my first post, but I had been putting off posting for so long, that I didn't even think to try and explain why I went down this path.

I have 2 cartridges that work out of the box with the adapter on my Megadrive II PAL:- Enduro Racer (Mark III)- Alex Kidd In Miracle World (Mark III)

Those 3 games will not boot without stack init. A trick that's mentioned on the Raphnet page is to swap a working cartridge quickly with a non-working one, while powered off. Another way, which I wouldn't recommend but works is to start the Megadrive with the adapter but not the cartridge, insert the cartridge and press Reset. Anyhoo, the 3 games:- Alex Kidd BMX Trial (Mark III)- Space Harrier 3D (Mark III/SMS)- Opa Opa (Mark III/SMS)

All 5 of those are detected as 4 megs "GenericRomInSegaSlot.dat" dumps. Dumping the ROMs ends up in garbage.

There's a few active components on the Mark III/SMD adapter, where the Retrode SMS adapter has none.

Hope that clears any doubts about the reason why I'm asking

(and if you want to share your pinout for the card reader, probably in a separate thread, it'd be appreciated!)

> @hadess whats wrong with just using that markiii to megadrive converter with the retrode? The schematic looks pretty straight forward so it should work.

Well, because it didn't work

I should probably have added this information in my first post, but I had been putting off posting for so long, that I didn't even think to try and explain why I went down this path.

I have 2 cartridges that work out of the box with the adapter on my Megadrive II PAL:- Enduro Racer (Mark III)- Alex Kidd In Miracle World (Mark III)

Those 3 games will not boot without stack init. A trick that's mentioned on the Raphnet page is to swap a working cartridge quickly with a non-working one, while powered off. Another way, which I wouldn't recommend but works is to start the Megadrive with the adapter but not the cartridge, insert the cartridge and press Reset. Anyhoo, the 3 games:- Alex Kidd BMX Trial (Mark III)- Space Harrier 3D (Mark III/SMS)- Opa Opa (Mark III/SMS)

All 5 of those are detected as 4 megs "GenericRomInSegaSlot.dat" dumps. Dumping the ROMs ends up in garbage.

There's a few active components on the Mark III/SMD adapter, where the Retrode SMS adapter has none.

Hope that clears any doubts about the reason why I'm asking

(and if you want to share your pinout for the card reader, probably in a separate thread, it'd be appreciated!)

i recreated the markiii to smd in eagle and stripped it down a touch, the resistors on it are just 0 ohm so i could just bridge the connections:

i will have to check it out sometime but currently i dont have any mark iii cartridges or console which sucks also i did have another thread for my sega card to master system adapter on here but i want to order some proper boards for it before i post everything and currently to get the sega card edge connector you have to remove it from a master system model 1 or something so that sucks.

this will probs be the best route to go down as it will most likely also work on a master system if your bios supports it.as for the retrode i cant remember if its setup to recognize mark iii roms so it will most likely show up as a .sms

I've just received skaman's prototype. The only problem I had was that I needed to power cycle the Retrode to make it read new carts.

I successfully dumped, without any tweaking necessary (ROM size, or otherwise), and compared them to ROM dumps on the net:Alex Kidd BMX TrialAlex Kidd no Miracle WorldEnduro RacerOpa OpaSpace Harrier 3D

Out of curiosity, I also tested with an SG-1000/SC-3000 cartridge (yes, cartridge, not card) of "Champion Golf" but ended up with a "GenericRomInSegaSlot".

I also got to put skaman's adapter through its paces today. The Retrode couldn't see the Mark III cart with my old firmware, so I updated to v0.22, and then it worked. My checksum for Phantasy Star matches the no-intro database, so I've applied the SMS Power English patch and am finally ready to experience the game with the proper soundtrack. Thanks skaman!

I'm also happy to report that firmware v0.22 is not generating USB errors in the Windows event log, so it appears that whatever USB problem was in the v0.18 firmware series is fixed now. My 3- and 6-button Genesis controllers are still working with the new firmware, so I'm not going to go back to v0.17g this time.